Fix NullRef in Collision::FromContact closes https://github.com/xamarin/urho-samples/issues/12
Fix NullRef in Collision::FromContact closes https://github.com/xamarin/urho-samples/issues/12

florin-chelaru/urho,florin-chelaru/urho,florin-chelaru/urho,florin-chelaru/urho,florin-chelaru/urho,florin-chelaru/urho